CANADIAN PUBLIC HEALTH JOURNAL
May, 1931, VOL. XXII, No. 5
Reduction in Diphtheria in 36,000 Toronto School Children as a Result of an Immunization Campaign
N. E. MCKINNON, M.B., MARY A. ROSS, M.A. AND R. D. DEFRIES, M.D., D.P.H.
Department of Epidemiology and Biometrics, School of Hygiene, University of Toronto
FROM December, 1926, to June, 1929, the Department of Public Health of the City of Toronto offered immunization against diphtheria, by the use of "toxoid" (anatoxine-Ramon), to the school children of the city. The administrative control of that under- taking, the various procedures that were used during the campaign, the records, the costs, etc., have been given in a previous communication. The purpose of this communication is to record the results.
As the physicians' notifications of diphtheria cases and the list of positive cultures were received daily by the Division of Medical Services of the health department the names were checked against the record cards of the campaign and tally was kept of each case of which there was record of test done or toxoid given. As the campaign progressed, this check gave indications on which certain changes in procedure, as shown in reference1, were based.
In the study of the results of the campaign and particularly of the efficiency of toxoid, the Department of Epidemiology and Biometrics of the School of Hygiene, University of Toronto, was kindly invited to co-operate. The records of all tests done, toxoid given, etc., were transferred accordingly to punch cards which were filed alphabetically in the Department of Epidemiology, School of Hygiene. At the end of each year all the notifications of diphtheria in the city and the quarantine inspectors' records were loaned to the Department of Epidemiology. Here, each notification of diphtheria was again checked against the punch card records and all cases identified in these were so punched and tabulated. Incorrect spelling of names, changed names, changed or incorrect addresses, etc., necessitated the utmost vigilance. Every suggestive name, if it could not be identified immediately in